Rex is asked by Jan Dennison to help find her brother Brad. Brad has been involved with Mara, owner of a casino and who has shady connections. The father of Jan and Brad is one of the wealthiest men in Louisiana, and is certain to disown Brad if he learns of Brad's relationship with Mara. It turns out Brad went to see Mara on her privately owned island -- where she has been hosting (for a $50,000 fee) two hoods who've pulled off a $250,000 bank robbery. Rex and Jan need to find Brad as Hurricane Teresa is bearing down on Louisiana -- and moving up the Mississippi River and heading toward Mara's island.